Process for breaking petroleum emulsions



fiatenteci July 29, 1952 PROCESS FOR BREAKING PETROLEiM EMULSION S Melvin De Groote, St. Louis, Mo., assignor to Petrolite Corporation, Ltd., Wilmington, DeL, a corporation of Delaware No Drawing. Application February 8, 1952, Serial No. 270,767

12 Claims. (01. 252-340) The present application is a continuation-inpart of my copending application Serial 'No. 179,401, filed August 14, 1950, now abandoned, which was a continuation-in-part and was copending with my application for Patent No. 2,552,528, dated May 15, 1951.

'This invention relates to petroleum emulsions of the water-in-oil typethat are commonly referred to as cut oil, roily oil, emulsified oil, etc., and which comprise fine droplets of naturally-occurring waters or brines dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion.

Onev object of my invention is to provide a novel process for breaking or resolving emulsions of the kind referred to.

Another object of my invention is to provide an economical and rapid process for separating emulsions which have been prepared under controlled conditions from mineral oil, such as crude oil and relatively soft waters orweak brines. Qontrolledemulsification and subsequent demulsification under the conditions ,just mentioned are of significant value in removing impurities, particularly inorganic salts from pipeline oil.

Demulsification as contemplated in the present application includes the preventive step of commingling the demulsifier with the aqueous component which would or might subsequently become either phase of the emulsion, in absence of such precautionary measure. Similarly, such demulsifier may be mixed with the hydrocarbon component.

In my aforementioned Patent No. 2,552,528, I have described a process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including high molal oxypropylation derivatives of a member of the class consisting of monomeric polyhydric compounds and monomeric polyhydric derivatives thereof which bear a simple genetic relationship thereto, with the proviso that: 7. r

(a) The initial. polyhydric reactant be free from any radical having at least 8 uninterrupted carbon atoms;

(b) The initial polyhydric reactant having a molecular weight not over 1200 and at least 4 hydroxyl radicals;

(c)- The initial polyhydric reactant be watersoluble and xylene-insoluble;

'(d) The oxypropylation end product be waterinsoluble and Xylene-soluble; '02), The oxypropylation end product be within the molecular weight range of 2,000 to -30,000 on an average statistical basis;

(f) The solubility characteristics of the oxypropylation end product in respect to water and xylene be substantially the result of the oxypropylation step; I a

(g) The ratio of propylene oxide 'per hydroxyl in the initial polyhydric reactant be' within'the range of 7 to '70; I f i (h) The initial polyhydric reactant represent not more than l2 by weight of the oxypropylation end product on a statistical basis, and (z') The preceding provisos being based on complete reaction involving the propyleneoxide and the initial polyhydric reactant. I

Furthermore, in said aforementioned patent I pointed out that such hydroxylated materials obtained .by'oxypropylation could be reacted with dicarboxy acids such as diglycollic acid to yield valuable derivatives which are satisfactor-y also for demulsification of petroleum emulsions.

The demulsifying agent employed in the present process is a fractional ester obtained from a polycarboxy acid and a polyhydrox'yla ted com pound obtained by the oxypropylation of a polyglycerol or etherized polyglycerol with the proviso that such etherized polyglycerol have-at least four hydroxyl radicals and that the. ether radical be derived from a monohydroxylated compound, such as an alcohol, phenol, or the like, having. less than 8 carbon atoms. Examples include the aliphatic; alcohols, alicyclic'alcohols such as hexanol and methyl hexanol, phenols such as hydroxy benzeneor cresol, benzyl alcohol and its alicyclic analogues, etc. My preference is that the ether group contain at least three carbon atoms and preferably be derived from a water-soluble alcohol such as propyl alcohol, butyl alcohol or amyl alcohol. In the case of butyl or amyl alcohols some of the. isomersare water-soluble to the extent'that they show solubility ofat least a few percent at room temperature. Other alcoholsgwhich can beem-L ployed include tetrahydropyran-Z-methanol and tetrahydrofurfuryl alcohol.

More specifically then the present invention is concerned with a process for breaking petroleum emulsions of the water-in-oiltype characterized. bysubjecting the emulsion to the action of 'a demusifier including hydropile synthetic products; said hydrophile synthetic products being the acidic fractional esters derived by reaction between (A) a polycarboxy acid and (B).high molal oxypropylation derivatives of polyglycerols I and ethersof polyglycerols, with the proviso that:

(a) The initial polyhydric reactant have at least 4 hydroxyl radicals;

(b) The initial polyhydric reactant be free from any radical having at least 8 uninterrupted carbon atoms;

The initial polyhydric reactant be watersoluble;

(d) The oxypropylation end product be waterinsoluble;

(e) The oxypropylation end product be Within the molecular weight range of 2,000 to 25,000 on an average statistical basis;

0) The solubility characteristics of the oxypropylation end product in respect to water and organic solvents by substantially the result of the oxypropylation step;

(9) The ratio of propylene oxide per hydroxyl in the original polyhydric reactant be within the range of 7 to 80; p

(h) The initial polyglycerol reactant represent not more than 12 /2,% by weight of theoxypropylation end product on a statistical basis, and

(i) The preceding provisos being based on complete reaction involving the propylene oxide and the initial polyhydric reactant; and (C) with the final proviso. that the reaction ratio of (A) to, ,(B) be one moleof (A) for each hydroxyl radical present in (B).

The preparation of glycerol, particularly diglycerol, is well known. For example, reference is made to the following patents; U. 5. Patents Nos. 1,126,467, 2,382,764, 2,477,550, and 2,487,208.

Ethers of polyglycerols can be prepared in any one of a number of ways. For example, the same procedure employed to convert glycerol into an ether can be employed generally to :convert, a polyglycerol into an ether.

As to patents that illustrate such procedures see U. S. Patents Nos. 1,959,930, 2,089,569, 2,164,007, 2,181,100, 2,221,818, 2,314,039, 2,380,185, 2,453,634, 2,413,860, 2,010,726, and 2,258,892.

See also pamphlettentitled Epichlorohydrin, issued by Shell Chemical Corporation, New York city, New York. 7 Since polyglycerol may be acyclic orcyclic itis obvious that formation of rings. eliminates hydroxyls and thus if in doubt a compound should be. examinedin' the usual manner to determine that there are at least four hydroxyl radicals present. Generally this involves nothing more than the molecular weight determination and a hydroxyl determination, particularly if the method of manufacture is known.

Other methods of manufacture are obvious; for example, reacting glycerol with one or more moles of glycide. Another procedure involves the reaction of an ether, such as glycerol alpha gamma di-isopropyl ether, with three or more moles of glycide. The same procedure can be employed in connection with glycerolflalpha gamma'diphenyl ether. Other procedures involve the-reaction of glycerol alpha allyl ethehglycerol alpha ethyl ether, glycerol alpha isopropyl. ether, glycerol alpha phenyl ether, 'or the" likejwith a mole of glycide. Another procedure involves the reaction. of diglycerolwith a mole .of allyl glycidyl ether, glycidyl isopropyl ether, glycidylzphenyl ether, or similar compounds. Needless ito. "say, anyone of a number ofreactionssinvolve theuse of epichlorohydrin or. a simple derivative thereof to yield hydroxylated compounds of the kind herein employed as initial raw materials.

Other procedures havebeen described, or are obvious, in which reactants such as glycerol monochlorohydrin, glycerol dichlorohydrin, and

with a polycarboxy acid so as to introduce one mole of the acid for each hydroXyl radical. Such esterification is conducted under comparatively mild conditions so as to prevent polymerization,

i. e., the final product is an acidic ester of the initial hydroxylated material and not a polyester.

For convenience, what is said hereinafter will be divided into five sections:

Part 1 is concerned with the preparation of the oxypropylation derivatives of the polyglycerol or polyglycerol ethers of the kind described;

Part 2 is concerned with the preparation of the esters from the oxypropylated derivatives;

Part 3 is concerned with the structure of the polyhydroxylated compounds and particularly after oxypropylation, and its relationship to methods of describing the ultimate demulsifiers;

Part 4 is concerned with the use of. the products herein described as demulsifiers for breaking water-in-oil emulsions, and

Part 5 is concerned with certain derivatives which can be obtained from the oxypropylated intermediates. In some instances such deriva-, tives are obtained by modest oxyethylation, preceding the oxypropylation step, or by oxypropylation followed by oxyethylation. This results in intermediates having somewhat different properties which can be reacted with the same polycarb-oxy acids or anhydrides described in Part 2 to give effective demulsifying agents. For this reason a description of the apparatus makes casual mention of oxyethylation. For the same reason there is brief mention of the use of glycide and also in the latter instance this is significant insofar that glycide has been specified as a reactant in this introductory presentation for the preparation of polyglycerols.

PART ONE For a number of well known reasons equipment, Whether laboratory size, semi-pilot plant size, pilot plant size, or large scale size, is not as'a rule designed for a particular alkylene oxide. invariably and inevitably, however, or particularly in the case of laboratory equipment-and pilot plant size the design is such as to use any of the customarily available alkylene oxide, i. e., ethylene oxide, propylene oxide, butylene oxide, glycide, epichlorohydrin, styrene oxide, etc. In the subsequent description of the equipment it becomes obvious that it is adapted for-ox yethylation as Well as oxypropylation.

Oxypropylations are conducted under a wide variety of conditions, not only in regard to presence of absence of catalyst, and the kind? of catalyst, but also in regard to the time of reaction, temperature of reaction, speed of reaction, pressure during reaction, etc. For instance, oxyalkylations can be conducted at temperatures up to approximately 200 C. with pressures inabout the same range up to about 200 pounds: per square inch. They can beLconducted also at-temperau s a roximat n .the'bpi oi of water orslightly above, as for example 95? to 120C. Under such circumstances the pressure will be less than 30 pounds per square inch unless some special procedure is employedas is sometimes the case, to wit, keeping at atmosphere of inert gas such as nitrogen in the vessel during the reaction. Such low-temperature-low reaction rate oxypropylations have been described very completely in U. S. Patent No. 2,448,664-to H. R. Fife et al., dated September '7, 1948. Low temperature, low pressure ox'ypropylationsare particularly desirable where the compound being subjected to oxypropylation contains, one, two or three points of reaction only, such as monohydric alcohols, glycols and triols.

The initial reactants in the instant application contain at least 4 hydroxyl groups and for this reason there is possibly less advantage in using low temperature oxypropylation rather than high temperature oxypropylation. I-Iow-v ever, the reactions do not go too slowly and this particular procedure was used in the subsequent examples.

Since low pressure-low temperature reaction speedoxypropylations require considerable time, for instance, 1 to 7 days'of 24 hours each to complete the reaction they are conducted as a rule whether on a laboratory scale, pilotplant scale, or large'scale, so as to operate automatically. The prior figure, of seven days applies especially to large-scale operations. l1 have used conventional equipment with two added'automatic features: (a) a solenoid controlled valve which shuts off the propylene oxide in event that the temperature gets outside a predetermined and set range, for instance, 95 to 120 C., and (b) another solenoid valve which shuts off the propylene oxide (orv for that matter ethylene oxide if it is'being used) if the pressure gets beyond a predetermined, range, such as 25 to 35 pounds. Otherwise, the equipment issubstantially the same as is commonly employed for this purpose where the pressure of reaction is higher, speed of reaction is higher, and time of reaction is much shorter. In such instances such automatic controls are not necessarily used.

Thus, in preparing the various examples I have found it particularly advantageous to use laboratory equipment or pilot plant which is designed to permit continuous oxyalkylation whether it be oxypropylation or oxyethylation. With certain obvious changes the equipment can be used also to permit oxyalkylaltioh involving the use ofglycide where no pressure is involved except the vapor pressure of a solvent, if any, which may have been used as a diluent.

As previously pointed out the method of using propylene oxide is. the same as ethylene oxide. This point ise'mphasized only for the reason that the apparatus is so designed and constructed as to use either oxide. v,

The ,oxypropylation procedure employed in the preparation of the oxyalkylated derivatives has been uniformly .the same, particularly in light of the fact that a continuous automatically-controlled procedure'was employed. In this procedure the autoclave was a conventional autoclave made of stainless steel and having'a capacity of approximately 15- gallons and a working pressure of one thousand pounds gauge pressure. This pressure obviously is far beyond any requirement as far as propylene oxide goes unless there is a reaction of explosive violence involved due to accident. The autoclave was equipped with the conventional devices and openings, such as the variable-speed stirrer operatingat speeds from 50 R. P. M. to 50O R. P. M.-; thermometer well and thermocouple for mechanicalithermometer; emptying outlet; pressuregauge, manual vent line; charge hole for initial reactants; at least one connection for introducing the alkylene oxide, such as propylene oxide or ethyleneoxide, to the bottom of the autoclave; along with suitable devices for both cooling and heating the autoclave, such as a cooling'jacket, and, preferably, coils in' addition thereto, with the jacket so arranged that it is suitable for heating with steam or cooling with water andfurther equipp d with electrical heating devices. Such autoclaves are, of course, in essence small-scale replicasof the usual conventional autoclave used in oxyalkylation procedures. In some instances in exploratory preparations an autoclave having a smaller capacity, for instance, approximately 3 liters in one case and about 1% gallons in another case, was used. I

Continuous operation, or substantially continuous operation, was achieved by the use of a separate containerto hold the alkylene oxide being employed, particularly propylene oxide. In conjunction with the smaller autoclaves, the container consists essentially of a laboratory bomb having a capacity of about one-half gallon,'or somewhat in excess thereof. In some instances a large bomb was used, to wit, one having a capacity of about one .gallon. This bomb was equipped, also, with an inlet for charging, and an eductor tube going to the bottom of the container so as to permit discharging of alkylene oxide in the liquid phase to the autoclave. A bomb having a capacity of about 60 pounds was usedin connection with the 15-gallon autoclave. Otherconventionalequipment consists, of course, of the rupture disc, pressure gauge, sight feed glass, thermometer, connection for nitrogen for pressuring bomb, etc. The bomb was placed on a scale during use. The connections'between the bomb and the autoclave were flexible stainless steel hose or tubing sothat continuous weighings could bemade without breaking or making any connections. This applies also to the nitrogen line, which was used to pressure the bomb reservoir. To the extent that it was required, any other usual conventional procedure or addition which provided greater safety was used, of course, such as safety glass protective screens, etc. r

Attention is directed again to what has been said previously in regard to automatic controlsv which shut off the propylene oxide in event temperature of reaction passes out of the predetermined range or if pressure in the autoclave passes out of predetermined range.

With this particular arrangement practically all oxypropylations become uniform in that the reaction temperature was held within a few degrees of any selected point, for instance, if C. was selected as the operating temperature the maximum point would be at the most C. or 112 C., and the lower point would be 95 or possibly 98 C. Similarly, the pressure was held at approximately 30 pounds within a 5-pound variation one way or the other, but might drop to practically zero, especially where no solvent such as xylene is employed. The speed of reaction was comparatively slow under such conditions as compared with oxyalkylations at 200 C. Numerous reactions were conducted in which the time varied from one day (24 hours) up to three days (72 hours), for completion of the final mem;

estates 7 ber-of a series. In someinstances"the reaction may take place in considerably less time, i.- e.-, 2-ihours or less, as--far= as apartialoxypropylation is concerned.-- Theminimum time'recordedwa's' about a 6-hour-period ina single'step. Reactions indicatedas beingcomplete in 7 or 8 hours may have been-complete in alesser-period-of time in light of the automatic equipment-employed. 7 In the addition of propylene oxide, in the autoclave equipment as far as possible the valves were set so all the proylene oxide if fed continuously would be added at a rateso that the predetermined .amount would react within the first hours of the 8-hour period or two-thirds of any shorter period. This-meant that if the reaction was interrupted automatically for aperiod of time for pressure todrop or temperature to drop the predetermined-amount of oxide would-still be added in most instances 'well'within the predetermined time period. Sometimes where the additionwas a comparatively small amount in an 8-hour period there wouldbe an unquestionable speeding up of the-reaction, by simply repeating the example and using 4; 5 orfihours instead of 8 hours.

When operating at acomparatively high temperature, for instance, between 150 to 209C; an unreacted alkylene oxide such aspropylene oxide, makes its presence felt in the increase, in pressure or theconsistencyof a high pressure. However, at a-low-enough-temperature it may happen that thepropyleneoxide goes in as a liquid. If so, and if it remains unreactedthere is, of course, an-inherent dangera-nd appropriate steps mustbe taken to'safeguard-against'this possibilitmif need be asample must'bewithdrawn and examined-iorunreacted propylene oxide. One obvious'procedure, of course, is to oxypropylateat a modestly higher temperaturajfor' instance, at 140 120 150 C. Unreacted oxide affects, determination of-theacetyl or hydroxylvalue, of the hydroxylated compoundobtained; V

The higher. the molecular weight of the com.- pound, i. e., towards the latter stages of reaction; the longer the time required, to add'aigiven' amount ofjoxide, One possible explanation is that the molecule, being larger, the opportunity forrandom reaction is decreased. Inversely, the lower the molecular weight the fasterthe reactiontakes place. For this reason,;sometimes at least, increasing the concentration; of the catalyst does not appreciably speed up the reaction, particularly whenthe product subjected to oxyalkylation has acomparativelyhigh' molecular weight; However-fas'has been" pointed out previously, operatingfata low pressure and" a low temperature eveninlarge scale operations as much as a Weele or-ten-day -time may lapse toobtain some of' the higher molecular weight derivatives from monohydric pr dihydric materials. r I v In a number of operati'ons the counterbalance scale or dial scale holding thelpropylene oxide bomb was so s'etthat when the predetermined amount of propylene oxide lra-d passedinto the reaction the-scale movement through a: time Oneratingd'evice was set for either one totwo hoursso that reaction continued forl "3h0111'8fiff61' the final addition of thelastpropylene oxide and thereafter the operation-was shut down Thisx particulardevice is particularly suitable for use on larger equipment than laboratory size autoclaves, to wit; on semi-pilot plant or'pilot plant size, as well as on large -scale-size. -T-his final stirring period -is-intended to avoid the presence of unr'eactedoxide:-

In; this of operation, of course,- the tendperature range was controlled automatically by eitheruseof cooling water, steam, or electrical heat, so as to raise or lower the temperature.

The pressuring of the propylene oxid into the reaction vessel was also-automatic insofar that the feedstream was set for'a slow continuous run which was shut ofi in case the pressure passed; ap fedetermined point as previously set out. All the'points of design, construction, etc., were conventional including the gases. check valves and entire equipment. As far as I am'aware at least two'firms; and. possibly three, specialize. in autoclave equipment such as'I have employed in the laboratory, and are prepared to furnish equipment of this same kind; Similarly pilot plant equipment is available. This point is simply made as a precaution in the direction of safety. (3xyalkylations; particularly involving ethylene oxide, glycide', propylene oxide, etc., should not be conducted except in equipment specifically designed'for thepurpose.

Example 1a setrfor injeotingatotal of. almost 62 pounds of propylene oxide in a 9-hour period. The pressure regulator was set for a-maximum of 35 pounds per square inch. However, in this. par:- ticular step andinallthe succeeding stepsthe pressure never got over 30 pounds per square inch. In fact, this -meant that the bulk of the reaction couldtake place. and did take placeat an appreciably lower pressure. This comparatively low pressure. was the. result of the fact that. considerable, catalyst. was present,. the propylene oxide was added comparatively slowly and, more. important,v the selected temperature rangewas205 to 215 F (about the boiling point of. water). The initial introduction of the propylene-oxide.was-not started until the hearing devices had raised-the temperature-to approximately the-boiling point ofwater. At the completion-0f the reaction a sample was taken and. oxy-propylationproceeded as in Example2a, immediately succeeding.

.ExampZeiZa.

45'po mds of the reaction mass identified'as Example M were permitted to remain inithe reaction; vessel and without the addition .of. any more catalyst approximately 16 pounds more of propylene oxide were added. The oxypropylation was conducted in substantially the same. manner in regard-to pressure and temperaturev as: in. Example; la, preceding, except that the, reaction was completed in six'hours. At the end of the reaction period part of the sample was: with! drawn and oxypropylation' was continued as de.- scribedinExample'Ba, following;

Example. 3w

Approximately 52% pounds of the reaction mass identified as Example 2a, preceding, were permitted to stay in the reaction vessel. About 26% pounds of; propylene; oxide were'introduced during this period. No additional catalyst was added. The

conditions of reaction as far as temperature and pressure were concerned were substantially the same as in Example 1a, preceding. The reaction time-was 7 hours. At the completion of the reaction, part of the reaction mass was withdrawn and the remainder subjected to oxypropylation as described in Example 4a, succeeding.

as described in Example la, as far as temperature and pressure were concerned. The time required for the addition of this oxide was 8 hours. What has been said herein is presented in 5 tabular form in Table 1 immediately following,

with some added information as to molecular weight and as to solubility of thereaction product in water, xylene and kerosene.

TABLE 1 I Composition Before Composition at End M. W. Max;

' IP31 Max 1 5 I Tim y s e, H. 0. Oxide Oata- Theo. H. o. 1 Oxide .Cata- Deter- W sq. Hrs.

Amt, Amt., lyst, M01. Amt, Amt., lyst, min. in.}

Lbs. Lbs. Lbs. Wt. Lbs. Lbs. Lbs.

6. 56 0.62 1, 745 6. 56 61. 83 62 1, 453 205-215 8% 4. 28 40. 32 2, 345 4. 28 56. 32 40 1, 745 205-215 30 6 3. 71 48. 70 34 3, 540 3. 71 75. 34 2, 630 205-215 30 7 2. 67 54. 08 25 4, 485 2. 67 69. 58 25 2, 810 205-215 30 6 2. 32 61. 84' 22 6, 585 2. 32 89. 46 22 3, 550 205-215 30 6 1. '38 64. 66 16 7, 765 1. 68 73. 91 l6 3, 760 205-215 30 5. 5 l. 52 66. 6- .13 9, 665 l. 52 87. 1' 13 3, 910 205-215 30 7 1.08 61. 83 09 10, 900 1.08 70. 83 .09 4, 275 205-215 30 8 'lhe hydroxylated compound is acyclic diglycerol.

Example 4a Slightly over 64 /3 pounds of reaction mass were permitted to remain in the autoclave. No additional catalyst was introduced. Slightly over 27% pounds of propylene oxide were introduced in the same manner as described in Example 1a, preceding. The conditions of temperature and pressure were substantially the same. The time required to introduce the oxide was 6 hours.

Example 6a Approximately 66 pounds of reaction mass werepermitted to stay in the autoclave. No additionalcatalyst was added. This was subjected to reaction with about 9 /4 pounds of propylene oxide. Conditions of reaction were substantiallythe same as described in Example 1a as far as temperature and pressure were concerned. The period required for addition of the oxide was 5%, hours.

Example 7a Approximately 68% pounds of reaction mass were permitted to stay in the autoclave. Without adding any more catalyst this was subjected to reaction with approximately 20 /2 pounds of propylene oxide. Conditions of reaction were substantially the sam' 'as described in Example la as far as temperature and pressure were con-- cerned. The time period required for the addition of this oxid e was 7 hours.

7 Example 8a Approximately 63 pounds of the reaction mass were permitted to stay in the autoclave. Without adding any more catalyst this was subjected to reaction with 9 pounds of propylene oxide. Conditions of reaction were substantially the same droxylated compounds.

Examples 1a and 2a were soluble in water.

25 Example 3a was not soluble but showed a tendency to emulsify. Example 4a was dispersible in water, i. e., did not emulsify as well asthe'previous example. Example 5a was largely insoluble in water, but a fraction of the mixture was dis- 0 persible. Also, note that Example 5a and allsuc;

ceeding examples were soluble in kerosene. Examples 1a, 2a and 3a were not soluble in kerosene. Example 4a was dispersible in kerosene. Ex: amples 1a through 8a were all soluble in xylene.

0 In all cases the oxypropylated derivative must be xylene-soluble and. is preferably water-insoluble.

My preference isto employ derivatives which are kerosene-soluble. Q I The final product, i. e., at the end of-the oxypropylation step, wasa somewhat viscous amber-colored fluid which was 'water -ins'olub le. This is characteristic of all various end products obtained in this series. 3 These products were. of course, slightly alkaline due to the residual caustic 45 soda employed. This'would also be-the case if sodium methylate were'used as a catalyst. 7

Speaking of insolubility in water or solubility in kerosene such solubility test can be made simply by Shaking small amounts of the mate-.-

50 rials in a test tube with water, for instance. us-

ing '1% to 5% approximately based on the amount of water present. 1

Needless to say, there is no completeconver- ,sion of propylene oxide into the desired hy- This is indicated by the fact that the theoretical molecular weight based on a statistical average is greater than the molecular weight calculated by usual methods on basis of acetyl or hydroxyl value. Actually, there is no'completely satisfactory'method for determining molecular weights of these types of compounds with a high degree of accuracy when the molecular weights exceed 2,000. In some. instances the acetyl value or hydroxyl value serves 165 as satisfactorily as an index to "the molecular weightas' any other procedure, subject to the above limitations, and especially in the higher molecular weight range. If any difiiculty is en'- countered in the manufacture of the esters as 70 described in Part 2 the stoichiometrical amount of acid or acid compound should be taken which corresponds to the indicated acetyl or hydroxyl 'value. This matter'has been discussed inith'e literature and is a matter of common knowledge and requires no further elaboration. In fact, it

l -l is illus'tra ted by some of 'he-emmmesappar mg in thepatent previously mentidn'ed.

Using a smaller autoclave, i. 'e., one having a capacity of slightly less t11a-n one gallon, I have prepared a number of similar compounds from di'g lycerol thers, for eiainple, the product obtained- 'b'y reactingonie ""ole' oi di'glycei'ol with one mole of glycidyl iso'pisp'yi "thr aiid' al'so with one mole of glycidyl phenyl ether. These ethers were oxypropylated in substantially the same manner and under substantially the-same conditions as in -E ';amples -10. through -8a, --preceding. lior sake of brevity the-data are suinmarized in the followingtable:

12 chloric'acid'gas "is-"to be 'used als a catalyst. 'Such devicecsr' abs Y ti'oh spradr cbilsists of-minute alundum thi'mb1es which are connected to a glass tube. Gnecan'add a suliorlic a'cid'such asparatol-u'ene sulfohicacid as a catalyst. 'There' is'solne objection 'to' this becausein some instances there issoine' evid'nce that this acid catalyst tends :to decompose or rearrange "oxypro'pylated compounds, and particularly likely to do so if the esterification temperature is too high. In the case of polycarboxy acids such as diglycollic acid, Whichds strong-1y acidic there is no need to add any catalyst. The 'use'of hydrochloric gas has one advantage over paratoluene sulfonic acid TA LE l H Molecular V Theo 'eti- Weight by 5? Reactant i cal Molecp- Hydroxyl No. I lar Weight Determination 93 'Diglycciol'tli'er obtained byreacting dig'lycerol 1, 778 1, 430

. with-glycidyl i'sopropyl ether mole for mole.

The above p'mau'cts were comparable in" 'c'al' appearance although somewhat rriore ke'ro- 'seri'e soluble and less *water soluble than the corresponding cnes der-iv'edfroin dig'l'yce'rol.

PART 2 A "prviefisiypemteu out "the present invencdnc'e'rhedwi-th acidicesters obtained'irom the xyprdpylated derivatives described in Part 'mrhediately preceding, and polycarb'oxy acids, ti

c'ulalfly dicarboiiy acids such asadipic acid, phthalic-acid, 'o'r anhydride, succinic acid, diglycollic' acid, s'ebacidacid; azelaic acid, aconitic acia' maieic acid 'oranhydr'ide, citraconic' acid or anhydride, "maleic acid or anhydride adducts as obtained by the -Diels=Alder reaction from reactants such "as m'aleic 'anhydride and -'cyclo- I 'pentadiene. 'Sucha'ci'ds'should be heat stable so they are not decomposed'duringesterification. They may contain as many as" 36 carbon atomS' as, for egarinme, the acids obtained by "'diinerization ofjuns'atiirated fatty "acids, unsaturated menbca'r taxy fattyacids, or unsaturated 'inono cafrbo'ky 'a'cids "having '18 carbon atoms. Reference to the" acid inthe-"hretdapperided"claims obviously includes the 'anhydrides or-- any-other 'obviousequivalents. My preference; ho'weven-is 't'o use'polycarboxy acids having not overdcarbon "atoms.

Y The production of esters "including acid esters (iracti'onal' esters) irom-pblycarboxy acids and *glycolsor other hydroxylated compounds=-is-well known. Needless tosay, various compounds may 'be used'such as'the low mola-l ester, the-anhydride, the "acyl" chloride; etc. However, for purpose of economy it is customary'to 'useei'ther the acid or the' anhydride. conventional procedure is emipl'oyed. on alabora'tory'scale one can employ a 'resin'pot of the Kinddescrib'ed in U. S; Patent No. 2,499,370, dated March 7,'1950,to De Groote'and Keis'er, and particularly with 'one more opening "to per'mit the use ofa porous spreader if hydroand that isthat at the-end of the reaction it'can be-removedbyflushing-out with nitrogen, whereas there is no-reasonably convenient means-available of removing the paratoluene sulfonic' acid or other sulfonic acid employed. If hydrochloric acid is employed one need only pass the gas throughat-a'n exceedinglyslow rate so 'as to-keep the reaction mass acidic. OnIy-a trac'e of ac'id need be present. 7 I have 'e'm'plo'ye'd hydrochloric acid-Ygasor'the aqueous acid'it'se'lf 'to eliminate 'tlie ifiitial basic material. M prererence; how ever, is' to use-no catalyst whatsoever and to i'nsure omplete'dryness of the polyglyc'erolas described in the finab p'rocedure -'just preceding Table 3.

The products obtained in Part 1 preceding may contain a basic catalyst. As a general procedure I have added an amount of half-concentrated'hydrochloric acid considerably in excess of what'is required to neutralize the residual catalyst. The mixture is shaken thoroughly and allowed to stand over-night. It is then filtered and refluxed with the Xylene present until the water can be separated in a phase-separating trap. As soon as the product is substantially free from water the distillation stops. This preliminary step can be carried out in the flask to be used for esterification. If there is any further deposition of sodium chloride during the reflux stage needless to say a second filtration may berequired. In any event the neutral or slightly acidic solution of the oxypropylated derivatives described in Part 1 is then diluted further with sufficient xylene,-decalin, petroleum solvent, or the like, so that one has obtained approximately a 65% solution. To this solution there is added a polycarboxylated reactant as previously described, such as phthalic anhydride, succinic acid or anhydride, diglycollic acid, etc. The mixture is refluxed until esterification is complete as indicated by elimination of water or drop in carboxyl value. Needless to say, if one'produces a half- 13 ester from an anhydride such as phthalic anhydride; no water is eliminated. However, if it is obtained from diglycollic acid, for example, water is eliminated. All such procedures are conven- 14 when a number of conventional procedures are used, and may retard esterification, particularly where there is no sulionic acid or hydrochloric acidpresent as'a catalyst. Therefore, I have tional and have been so thoroughly described in preferredto use the following procedure: I have the literature that further consideration will be employed about 200 grams of the polyglycerol limited to a few examples and a comprehensive described in Part" .1, preceding; I have added tabl v about 60 grams of benzene, and then refluxed this Other precedures for eliminating the basic resimixture in the glass resin pot using a phase-sepadual catalyst, if any, can be employed. Forex- 0 rating trap until the benzene carried out all the ample, the oxyalkylation can be conducted in water present as water of solution or the equivaabsence of a solvent or the solvent removed after lent; Ordinarily this refluxing temperature is oxypropylation. Such oxypropylation end prodapt tobe in the neighborhood of 130 to possibly not can then be acidified with'just enough con- 150 C. When all this water or moisture has -centrated hydrochloric acid to just neutralize-the 15 beenremoved I;also withdraw approximately residual basic catalyst. To this product one can grams or a little less benzene and then add the then add a small amount of anhydrous sodium required amount of the carboxy reactant and also sulfate (suflicient in quantity to take up any about 150 grams of a high boilin aromatic pewater that is present) and then subject the mass troleum. solvent. These solvents are sold by to centrifugal force so as to eliminate the hy- 20 :various oil refineries and, as far as solvent effect drated sodium sulfate and probably the sodium act as if they-werealmost completely aromatic chloride formed. The clear somewhat viscous incharacter. Typical distillation data in the straw-colored amber liquid so obtained may conparticular type I have employed and found very tain a small amount of sodium sulfate or sodium satisfactoryis the .following: chloride but, in any event, is perfectlyacceptable L PW 0 m1" for esterrfication 1n the manner described. 5 m1" 2000a m1.

It s to be pointed out thatthe products here 10 m1" m1" 5 described are not polyesters 1n the sense that m1" 0 m1" there is a plurality of polyglycerolradlcals and 20 m1" m1" 0 C acid radicals; the product is characterized by 30 25 m1" m1" having only one polyglycerol radical. 30 m1. 30 m1" 0 In some instances and, in fact, in many in- 35 m1" C m1" stances I have found that in spite of the dehy- 40 m1" 2340 C. m1" C. dration methods employed above that a mere 45 m1" 0 C. trace of water still comesthrough and that this 3., After this material is added, refluxing com mere trace of water certainly interferes with the tinned and of course is at a higher temperature acetyl or hydroxyl value determination. at least TABLE 3 Theo. M01. t of Ex.No. Theo Actual Amt..of 9 of Hy- Mol Hy- Weight Hyd. Polycarboxy Polycar of Acid droxyl Based on boxy Ester droxy W. of V of droxyl Actual Gmpd. Reactant React t Cmpd H. O. H 0 Value H. V 151s.) (Q5311 12 8.5 154 1,453 200 DialycollicAcld... 73 g 122.5 154 1, 455 200 Phthalic Anhyd... 8() 2 128.5 154 1,453 200 Ma1cicAnyhd 54 125.5 154 1,453 200 40071111011010"... 95,0 128.5 154 1.453 200 Adioic Acid 05 128.5 154 1,453 200 Digl collic Acid... 73 3 128.5 154 1,453 200 Ma1eicA11hyd..... 54,0 128.5 154 1,455 200 ...do 4, 98.4 131 1,745 200 Diglycollic Acid... 5L6 98.4 131 1,745 200 Phthalic Anhyd... ago 98.4 131 1,745 200 Accnitic Acid.. 300 98.4 131 1.745 200 Maleic Anhyd. 45 98.4 131 1, 745 200 1101010 4010 57.1 98.4 131 1,745 200 Ma1eicAnhyd.... 45 70.0 55.0 2.530 200 1311110001110 Acid... 4 76.9 85.0 2,630 200 aleic Anhyd. 2113 70.9 85.0 ?,F30 200 Phthalic Anhyd 45 3 70.9 85.0 2, 030 200 Adipic 20171.... 44,3 76.9 85.0 2, 630 200 AconiticAcid-... 51 7 .9 85.0 30 200 Maleic Anhyd. mg 50.0 79.7 2, 810 200 Diglycollic Acid... 33, 50.0 70.7 2,510 200 Phthalic 4011 111.. 42,2 50.0 79.7 810 200 Aconitic Acid..." 40.6 1 50.0 79.7 2, 510 200 Maleic 51110 11.... 270 50.0 79.7 2,8 0 200 AdipicAcid 4L7 34.0 63.1 3,550 200 Diglvcollic Acid... 30,1 34.0 3.1 3, 550 200 Phthalic Anhyd 33 3 34.0 53.1 3,550 200 Maleic Anhyd.... 22.2 34.0 63.1 3, 550 200 Aconitic Acid... 39.2 34.0 53.1 a, 550 200 1171101040101 32 28.8 59.0 5,750 200 1311111 001110.4010... 2&4 28.8 50.5 3,7 0 200 Phthalic Anhyd... 31,4 25.5 50.6 3,750 200 Maleic A010 20.3 1 28.8 59.6 3,760 200 Aconitic Acid. 3 .9 28.8 59.0 3,701 200 Adipic 2411113 11.... 31.0 22.2 47.3 5,010 200 1210117001110 Acid... 301 1 23.2 47.3 3,910 200 Maleic 1411115711.... 22.1 23.2 47.3 3,910 200 Phthalic Anhyd.. 53.3 25.2 47.3 3,910 200 40011151040111.--" 59.0 23.2 47.3 3,910 200 21011 10 Acid 32.2 20.0 52.4 4,275 200 111 15 001110 Acid... 25.0 20.0 52.4 4,275 200 Phthalic Anhyd.. 27.7 20.6 52.4 4,275 200 Maleic Anhyd. 18.4 20.5 52.4 4,275 200 11001111510 Acid..... 52.0 20.5 52.4 4,275 200 0151000510 Anhyd. 21.1

1 These samples were not entirely satisfactory so were discarded and mum, using approximately 20% less acid in each instance and approximately 10 to 20 lower temperature during esterification.

tillation and. provided there' is no objection to a .little residue. .7 Actually, "when these materials are used for apurpose such as "demulsification the solvent'might justas well be'allowed toreniain. If the solvent is to be-removedbydistillati'on, andparticularly vacuum distillation; 'then the high boiling aromatic" petroleum solvent might well be-replaced-by some more expensive solventfsuch as decalinor'an alkylated decalin which has a rather definite or close range boiling point. The "removal of the solvent, of course,

is purely a conventional procedure and requires no elaboratiom- I V In the "appended table solvent #7-3, which appears inntrinerbusinstances, is a mixture of 7 volumes er the aromatic petroleum solvent previously described and 3 volumesof benzene. Referenceto solvent #7 means the particular petroleumlsolvent previously described in detail. This was used, or a similar mixture, in the manner previously described. A large number of the examples indicated employing decalin were repeated, using this mixture and particularly with the preliminary step of removing all the Water. solvent my preference is to use the petroleum solvent-benzene mixture although obviously any of the other mixtures, such as decalin and Xylene, can be employed.

The data included in the preceding and following tables, i. e., Tables 3 and 4, are self-explanatory, and very complete and it is believed no further elaboration is necessary.

TABLE 4 Max. Ester- Amt. Time of "Rx. No. cf t 801- fi l Esteriii- Acid Ester "vent 1 5B? cation 2 254 190' 3 7. 2 #7 282 161 4 O. 5 #7 254 197 4% Decali'n I287 204 5 13.5 #7 271 245 5% 10.0 #7 264 220 2 5 '9. 4 #7 254 210 None 60' #7 254 171 3 #7 254 '183 2% I 7. 5 #7 269 210 11% None #7 3 272 224 6 7. 2 #7 246 151 4 None #7 268 212 8 8. 2 #7-3 246 T158 5 None 65 -#7 ;235 207- 6% 7. 0 #7-3 229 230 M None #7-3 243 142 4% None #7-3 239 212 V 4% 3 #7-3 247 194 2% 5. 2 #7-3 229 141 4% None #7-3 233 172 4 5.1

-3 238 1 38 6 /4 None 70 #7-3 245 186 4% 4. 9 #7-3 228 ;139 4% None #73 236 176 4. 4 #7-3 226 173 3% 4. 0 #7-3 233 167 5% None #753 222 152 5 None #7- 3 235 180 11% 4.1 #7-3 229 195 17% 3.0 75

My:preference is not to go above If one does not intend to remove the Max. Ester- "Amt. Time of v ification v Water Solvent 'Tempcra- F out nerd Ester vent cation (cc) l (e c ff w s.) 7

22 4 163 8, 4 53- 230 143 5 None 220' 146 25%. None 228, 178 3% ,3.8 227 190 17 3.4 224 212' 5. 4:6 220 .151 ,5 None 230 191 '5 0.2 {232 202 i356 53,6 226. 228 11% 3.2 '222 j 4% 3; 4 228 134, 6% None 218 ,151 5% None 230 2 11- 5% an 221 144 2 None The procedure 'for manufacturing the esters has been illustrated by preceding examples. It for any reason reaction does not take place ina manner that is'acceptable, attention should be directed to the: following details: (a) Recheck the hydroxyl or acetyl value of the oxypropylated polyglycerol and use a stoichiometrically equivalent amounto'f acid; (b) .if the reaction does not proceed with reasonable speed either raise the temperature indicated 'or-else extend the period of time" up to 12 or 16 hours if need bej' (c) if necessary, use or" .paratoluene sulfonic acid or some other acid as a catalyst; (d) if the esterification does not produw a clear product a check should-be made to see if an inorganic salt such as sodium chloride or sodium sulfate'is not precipitating out. Such salt should be eliminated, at least for exploration experimentation, and can be removed by filtering. Everything else being equal as the size of the molecule increases the reactive hydroxyl radical represents a smaller fraction of the entire molecule and thus more difiiculty is involved in obtaining complete esterificaticn.

Even under the most carefully controlled conditions of oxypropylation involving comparatively low temperatures and long time of reaction there are formed certain compounds whose composition is still obscure. Such side reaction products can contribute a substantial proportion of the final cogeneric reaction mixture. Various suggestions have been made as to the nature of these compounds, such as being cyclic polymers of propylene oxide, dehydration products with the appearance of a vinyl radical, or isomers of propylene oxide or derivatives thereof, i. e., of an aldehyde, ketone, or allyl alcohol. In some instancesan attempt to react the stoichiometric amount of a polycarboxy acid with the oxypropylated derivative results in an excess of the carboxylated reactant for the reason that apparently-under conditions of reaction less reactive hydroxyl radicals are present than indicated by the hydroxyl value. Under such circumstances there is simply a residue of the carboxylic reactant which can be removed by filtration or, if

desired, the esterification procedure can be repeated using an appropriately reduced ratio of carboxylic reactant.

Even the determination of the hydroxyl value and conventional procedure leaves much to be desired due either to the cogeneric materials previously referred to, or for that matter, the

presence of any inorganic salts or propylene oxide.

Obviously this oxide should be eliminated.

The solventemployed, if any, can be removed from the finished ester by distillation and particusame procedure using decalin or a mixture of decalin or benzene in' the same manner and ultimately removed all the solvents by vacuum distillation. Appearances of the final products after esterification are much the same as the polyglycerols before esterification and in some instances were somewhat darker in color and had a reddish cast and perhaps'somewhat more viscous.

, PART 3 y In the hereto appended claims the demulsifying agent is described as an ester obtained from a polyhydroxylated material having at least four hydroxyls. If one were concerned with a monohydroxylated material or a dihydroxylated material one might be able to writea formula which in essence would represent the particular product. However, in a more highly hydroxylated material the problem becomes increasingly more diiiicult for reasons which have already been indicated in connection with oxypropylation and which can be examined by merely considering for the moment a monohydroxylated material.

oxypropylation involves the same sort of variations as appear in preparing high molal polypropylene glycols. Propylene glycol has a secondary alcoholic radical and a primary alcohol radical. Obviously then polypropylene glycols could beobtained, at least theoretically, in which two secondary alcoholic groups are united or a secondary alcohol group is united to a primary alcohol group, etherization being involved, of course, in each instance. Needless to say, the same situationv applies when one has oxypropylated and polyhydriclmaterials having 4 or more hydroxyls. Usuallyno'eifort is made to differentiate be tween oxypropylation taking place, for example, at the primary alcohol unit radical or the secondary alcohol radical. Actually, when such products are obtained, such as a high molal polypropyleneglycol or the products obtained in the mannerherein described one does not obtain a single derivative such as HO(RO)nI-I or -(RO)1:H in which n has one and only one value, for instance, 14, 15 or 16, or the like. Rather, one obtains a cogeneric mixture of closely related'or touching homologues. These materials invariable-have high molecular weights andeannot be separated from one another by any known procedure without decomposition. The properties of such mixture represent the contribution of the various indvidiual members of the mixture. one statistical basis, of course, n can be appropriately specified. For practical purposes one need only consider the oxypropylation of a monohydric alcohol because in essence this is substantiallythe mechanism involved. Even in such instances where one is concerned with a monohydric reactant one cannot draw a single formula and say that by following such procedure one canreadily obtain or or of such compound. However, in the case of at least monohydricinitial reactants one can readily draw the formulas of a large number of compounds which appear in some of the probable, mixtures or can be prepared as components and mixtures which are manufactured conventionally,

Simply by way of illustration reference is made to the De Groote, Wirtel and Pettingill Patent No. 2,549,434, dated April 1'7, 1951, the applica tion for which was copending with my copending application Serial No. 179,401 noted'abovea However, momentarily referring again to a monohydric initial reactant it is obvious that if one selects any such simple hydroxylated compound and subjects such compound to oxyalkyla tion, such as oxyethylation, or oxypropylation, it

becomes obvious that one is really producing a polymer of the alkylene oxides except for the terminal group. This is particularly truewhere the amount of oxide added is comparatively large," for instance, 10, 20, 30, 40, or 50 units. If such compound is subjected to oxyethylation so; as to" introduce 30 units of ethylene oxide,'it is well 1 known that one does not obtain a single constituent which, for the sake of convenience, maybe indicated as RO(C2H4O)30H. Instead, one "obtains a cogeneric mixture of closely related homologues, in whichthe formula maybe shown as the following, RO(CzH4O)nH,-wherein n, as far as the statistical average goes, is 30, but the individual members present in significant amount may vary from instances where n has a value of 25, and perhaps less, to a point where n may represent 35 or more. Such mixture is, as stated, a cogeneric closely related series of touching homologous compounds. Considerable inves'tig'ation has been made in regard to the distribution curves for linear polymers; Attention isdirected to the article entitled Fundamental principles of condensation polymerization, by Flory, which appeared in Chemical Reviews, volume 39, No. 1

page 137.

Unfortunately, as has been pointed out by Flory and other investigators, there is noSatisfactory method, based on either experimental or culty, it is necessary to resort to some other method of description, or else consider the value of n, in formulas such as those which haveappeared previously as representing both individual constituents in which n has a single definite value, and also with the understanding that n represents the average statistical value based on the assumption of completeness of reaction.-

This may be illustrated as follows: Assume that'in any particular example the molal ratio of propylene oxide per hydroxyl is 15 to 1. In a generic formula 15 to 1 could be 10,20, ors'o'me' other amount and indicated by n. Referring to this specific case actually one obtains products in which n probably varies from 1-0 to 20, perhaps even further. The average value; however," is 15, assuming, as previously stated, that the re-' action is complete. The product described; by

the formula is best described also in terms of method of manufacture.

The significant fact in regard to the t xfyprs-f pylated polyglycerols and the ethers thereof, and particularly those obtained from acyclic digly io I weight range in excess of 2,00 p din in part whether the initial product is'etherized or not and the size of the ether-ized radical, one o6taiiis water insolubility. The product may tend 'toemulsify or disperse somewhat because some: the constituntsbeing a cogeneric mixture, are water-soluble but the bulk are insoluble. Thus (means emulsifiability or dispersibility as noted. ,Such products are invariably xylenesolubleregardless of whether "the original reactants" were or'not. In numerous instances usually; at a; theoretical molecular weight range of approximately twicefth'e above, i. e., about 51,000, QtQ PlYTi Q h Prddu' fi silbstahiielly Wa l ll b q bu it is e pse r l I have} iQllFlt' e e".k r efier b e xra ii re n ts te-g at desira le iq w a in th es e s, have preparedhydroxylated derivatives not only up to the theoretical molecular weights shown buta-lsoup to twice this value, 1. e., approximate- 13 25,000, Some of these were prepared from triglycerol, tetraglycerob and pentaglycerol. These in turn were prepared from glycerol or diglycerol and glycide. The exact composition is open to questioninsofar that it is approximately a mixture of polyglycerol plus an extremely small amount or initial reactant present. The reasons are obvious because the same conditions are maintained in oxyalkylation with glycide as with oxide. It is interesting to note, however, that the molecular weights based on hydroxyl determinations at this point were considerably less, in the neighborhood of one-third or onefourth this value, i. e., 6,000 to 7,000, and inajew instances, 8,000. It becomes obvious when polycarboxylic esters are prepared from such high molecular weight materials there cannot be more terminal hydroxyls than were present initially, for instance, 4, 5, 6, '7 8 or possibly 10;or 12. Likewise, thejcontribution to the total molecular weight made by the polycarboxy acid is small. By the same token one would expect the, eifectiveness of the-demulsifier to be comparable to the unesterified hydroxylated material. Remarkably enough, in many instances the prod-- uct was distinctly better. This istrue, also, of certain other derivatives referred to in my aforementioned PatentNo, 2,552,528, and is true, also, in regard to what is said subsequently in Part 5.

7 PART 4 Toas master deadenin agents employed in the treatment of oil field emulsions are used as such, or after dilution with any suitable solvent, such as water,- petroleum hydrocarbons, such as benzene, toluene, xylene, tar acidoil, cresdLanthracene oil, etc. 7 Alcohols, particularly aliphatic alcohols, suchas methyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, butyl It'is wen 'knowntnat'dntntionai demulsify- Moreover, said material or mas-a 20 ing agents may be used in a water-soluble form, or in an oil-soluble form, or in a form exhibiting both 011- and water-solubility. Sometimes they may be used in a form which exhibits relatively limited oil-solubility. However, since such reagents are frequently used in a ratio of l to 10,000 or 1 to 20,000, or 1 to 30,000, or even 1 to 40,000, or 1 to 50,000 as in desalting practice, such an apparent insolubility in oil and water is not significant because said reagents undoubtedly have solubility within such concentrations. This same fact is true in regard to the material or materials employed as the demulsifying agent of my process.

In practicing my process for resolving petroleum emulsions of the water-in-oil type, a treating agent or demulsifying agent of the kind above described is brought into contact with or caused to act upon the emulsion to be treated, in any of the various apparatus now generally used to resolve or break petroleum emulsions with a chemical reagent, the above procedure being used alone or in combination with other demulsifying procedure, such as the electrical dehydration process.

One type of procedure is to accumulate a volume of emulsified oil in a tank and conduct a batchtreatment type of demulsification procedure to recover clean oil. In this procedure the emulsion is admixed with the demulsifier, for example by agitating the tank of emulsion and slowly dripping demulsifier into the emulsion; In some cases mixing is achieved by heatingthe emulsion while dripping in the demulsifier, depending upon the convection currents in the emulsion to produce satisfactory admixture. In a third modification of this type of treatment, a circulating pump withdraws emulsion from, e. g., the bottom of the tank, and reintroduces'it into the top of the tank, the demulsifier being added, for example, at the suction side of said circulating pump. 1

In a second type of treating procedure, the demulsifier is introduced'into the well fluids at the well-head or at some point between the well-head and the final oil storage tank, by means of an adjustable proportioning mechanism or proportioning pump. Ordinarily the flow of fluids through the subsequent lines and fittings suffices to produce the desired degree of mixing of demulsifier and emulsion, although in some instances additional mixing devices may be introduced into the flow system. In this general procedure, the system may include various mechanical devices for withdrawing free water, separating entrained water, or accomplishing quiescent settling of the chemicalized emulsion. Heating devices may likewise be incorporated in any of the treating procedures described herein.

A third type of application (down-the-hole) of demulsifier to emulsion is to introduce the demulsifier either periodically or continuously in diluted or undiluted'form into the well and to allow it to come to the surface with the well fluids, and then to flow the chemicalized emulsion through any desirable surface equipment, such as employed inthe other treating procedures. This particular type of application is decidedly useful when the demulsifier is used in connection with acidification of calcareous oil-bearing strata, especially if suspended in or dissolved in the acid employed for acidification. I

In all cases, itwillbe apparent from theforee d i tion the brea qc slfiqn st simply in introducing a relatively small proporonoi d mu sifie int a g e large op rtion of emulsion, admixing the chemical and emulsion either through natural flow or through 7 the emulsion separatesand settles from themass.

The following is a typical installation. A reservoir to hold the demulsifier of the kind described (diluted or undiluted) is placed at the.

wellhead where the eilluent liquids leave the well. This. reservoir or container, which may vary from 5 gallons 130.50 gallons for convenience,

is connected to a proportioning pump'which injects the demulsifler drop-wise into the fluids leaving the well. Such chemicalized fluidspass through the flowline into a settling tank. The settlingtank consists of a tank of any convenient size, forinstance, one which will hold amounts offluid produced in 4 to 24hours (500 barrels to 200 Q ,ba rrels capacity), and in which there is a perpendicularconduit from the top of the tank to almost the very bottom soas to permitthe incoming fluids to pass from the top of the settling tank to the bottom, so that such incoming fluidsdo not disturb stratification which takes place during the course of demulsification. The settling tank has two outlets, one being below; the water level to drain off the water resulting from demulsification or accompanying the emulsion as free water, the other being an oil outlet at the top to permit the passage of dehydrated oil to a second tank, being a storage tank, which holds pipeline or dehydrated oil. If V desired, the conduit or pipe which serves to carry the fluids from the well to the settling tank may include a section of pipe with bafiles to serve asmulsifier being added is just suflicient to produce 1 clean or dehydrated oil. The amount being fed at such stage is usually 1:10,000, 1:15,000, 1:20.000, or the like.

In many instances the oxyalklatedproducts herein specified as demulsifiers can be conveniently used without dilution. However, as previously noted, they may bediluted as desired with any suitable solvent. For instance, by mixing 75 parts by weight of an oxyalkylated derivative, for example, the product of Example 31b with 15 parts by weight of xylene and 10 parts by Weight of isopropyl alcohol, an excellent demulsifier is obtained. Selection of the solvent will vary, de-

pending upon the solubility characteristics of the 22 An ammonium salt of a polypropylated naph thalenemono-sulfonio acid, 24%

A sodium salt of oil-solube mahogany petro-' leum sulfonic acid, 12%

A high-boiling aromatic petroleum solvent,

Isopropyl alcohol, 5%.

The above proportions are all weight percents.

PART 5 Previous reference has been made to other oxyalkylating agents other than propylene oxide,

such as ethylene oxide. Obviously variantscan be prepared which do not depart from what is .said herein but do produce modifications. .The V polyhydroxylated compounds employed as intermediates can be reacted with ethylene oxide in modest amounts and then subjected to oxypropylation provided the resultant derivative is (a) comparatively water-insoluble as previously noted or at least beyond 2,000 on the theoretical Weight basis previously noted and is preferably kerosene-soluble and in any event xylene-soluble and has from 7 to 80 alkylene oxide radicals per initial hydroxyl radical. to have water-insolubility and kerosene-solubility the large majority must be propylene oxide. Other variants suggest themselves as, for example, replacing propylene oxide by butylene oxide. l

Needless to say the, one mole of diglycerol, triglycerol, or a similar polyglycerol orether thereof can be treated with a small amount of ethylene oxide and then treated with propylene oxide-so" as to produce preferably the water-insoluble, kerosene-soluble derivative having 7 to80'oxide radicals per initial hydroxyl as previously indicated. Similarly the propylene oxide can be added first and then the ethylene oxide, or random oxyalkylation can be employed using amixture of the two oxides. The compounds so ob tained are readily esterified in the same manner a as described in Part 2, preceding. Incidentally, the polyhydroxylated compounds described in I Part 1 or the modifications described therein can be treated with various reactants such as glycide, epichlorohydrin, dimethyl sulfate, sulfuric acid, maleic anhydride, ethylene imine, etc. If treated with epichlorohydrin or mono chloroacetic' acid the resultant product can be further reacted with a tertiary amine such as pyridine, or the like, to give quaternary ammonium compounds. If treated with maleic anhydride to give atotal ester the resultant can be treated with sodium bisulfite to yield a sulfosuccinate. Sulfo groups can be introduced also by means of a sulfating agent as previously suggested, or by treating the chloroacetic acid resultant with sodium sulfite.

I have found that if such hydroxylated compound or compounds are reacted further so as to produce entirely new derivatives, such new derivatives have theproperties of the original hydroxylated compound insofar that they are effective and valuable demulsifyingagents forresolution of water-in-oil emulsions as found in the Needless to say, in order games I hydrophile synthetic products being the acidic fractional esters derived by reaction between (A) I a polycarboxy acid and (B) high molal oxypropylation derivatives of polyglycerols and ethers of polyglycerols, with the proviso that (a) the 5 initial polyhydric reactant have at least 4 hydroxyl radicals; (b) the initial polyhydric reactant be free from any radical having at least '8 uninterrupted carbon atoms; (0) the initial polyhydric reactant be Water-soluble; (d) the oxypropylation-endproduct be water-insoluble; (e) the oxypropylation end product be within" the molecularweight range of 2,000 to 25,000 on an average statistical basis; (I) the solubility-characteristics of the oxypropylation 'endproduct in respect to water and organic solvents be substantially the result of the'oxyprcp'ylation step; (9) the ratio of propylene oxide perhydroxyl in the original polyhydric reactant 1 be within the range of 7 to 30; (h) theinitial polyglycerol reactant represent not more than '12 by weight of the oxypropylation end product on a statistical basis; and (i) the preceding provisos being based on complete reaction involving the propylene oxide and the initial polyhydric reactant; and (C)' With'the final proviso that the reaction ratio of (A) to (B) be one mole of (A) for each hydroxyl radical present in (B) 2. A-process for breaking petroleum emulsions 0f the water-in-oil type characterized by subjecting'the'emulsion to the-action of a d'emulsi-fier including hydrophile synthetic products; said hydrophile synthetic products being the acidic fractional esters derivedby reaction between (A) a polycarboxy acid and B high molal oxypropylation derivatives of po'lyglycerol's, with the proviso that (a) the initial polyhydric reactant have at least 4 hydroxyl radicals; (b) the initial polyhydric reactant be free from any radical having at least 8 uninterrupted carbon atoms; (c) the initial polyhydric reactant be watersoluble; (d) the oxypropylation endproduct bewater-insoluble; (e) the oxypropylation end-prodnot be within the molecular weight range of 2,000 to 25,000 on an average statistical 'basis; (f) the solubility characteristics of the oxypropylation end product in respect to water and organic solvents be substantially the result of the oxypropylation step; (g) the ratio of propylene oxide per hydroxyl in the originalpolyhydric reactant be within the range of 7 to 80; (h) the initial polyglycerol reactant represent not more than 12 /2 by weight ofthe oxypropylation endprod not one statistical basis; and (i) the preceding provisos being based on complete reaction in -55 volving the propylene oxide and the initial polyhydric reactant; and (C) with the final proviso that the reaction ratio of (A) to- (B) be one mole of (A) for each hydroxyl radical present in (*B).

3. The process of claim 2 with the provisothat 00- be soluble in both xyleneand kerosene;

24 5. 'A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting'the emulsionto the action of a demulsifier including hydrophile synthetic products; saidxylene and kerosene; (d) the solubility charac teristics of the oxypropylation end productjinrespect to water and organic solvents be substantially theresult of the oxypropylation step; (e) the ratio of propylene oxide per hydroxyl in the original diglycerol be within the range of 7 to (f) the initial diglycerol represent not more than 12 by weight of the oxypropylation end product on a statistical basis; (9) the preceding provisos being based on complete reaction involving the propylene oxide and the initial polyhydric reactant; and '(C) with the final proviso that the reaction ratio of (A) to (B) be one mole of (A) for each hydroxyl radical present in (B).

6. The process of claim 5 with the proviso that the theoretical molecular'weight be within the range of 2,000 to 10,000.

7. The process of claim 5 with the proviso that the theoretical molecular weight be Within the range of 2,000 to 10,000 and that the polycarboxy acid be dicarboxy acid.

8. The process of claim 5 with the proviso that the theoretical molecular weight be within the range of 2,000to- 10,000 and that the polycarboxy acid be phthalicacid. I

9.: The process of claim 5 with the proviso that the'theoretical molecular weight be within the range of 2,000 to 10,000 and that the polycarboxy acid be maleic acid.

10. The process of c1aim-5with the proviso that the theoretical molecular weight be within the range of 2,000 to 10,000 and that the polycarboxy acid be succinicacid.

11. The process of claim 5 with the proviso that the theoretical molecular weight be within the rangeef- 2,000 to-1'0-,000 and that'the polycarboxy acid be citraconic acid.

12. The process of claim 5 with the proviso that the theoretical molecular weight be within the range of 2,000to 10,000 and that the polycarboxy acid be di-glycolicacid.

MELVIN DE GROOTE.

REFERENCES CITED The following references are of record in the file of this: patent:

UNITED STATES PATENTS Number Name Date 2,507;560 De Groote et al. May 16, 1950 2,514,399 Kirkpatrick et a1. .Ju1y11, 1950 2,562,878 Blair Aug. 7, 1951 

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPE CHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIER INCLUDING HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETIC PRODUCTS BEING THE ACIDIC FRACTIONAL ESTERS DERIVED BY REACTION BETWEEN (A) A POLYCARBOXY ACID AND (B) HIGH MOLAL OXYPROPYLATION DERIVATIVES OF POLYGLYCEROLS AND ETHERS OF POLYGLYCEROLS, WITH THE PROVISO THAT (A) THE INITIAL POLYHYDRIC REACTANT HAVE AT LEAST 4 HYDROXYL RADICALS; (B) THE INITIAL POLYDRIC REACTANT BE FREE FROM ANY RADICAL HAVING AT LEAST 8 UNINTERRUPTED CARBON ATOMS; (C) THE INITIAL POLYHYDRIC REACTANT BE WATER-SOLUBLE; (D) THE OXYPROPYLATION END PRODUCT BE WATER-INSOLUBLE; (E) THE OXYPROPYLATION END PRODUCT BE WITHIN THE MOLECULAR WEIGHT RANGE OF 2,000 TO 25,000 ON AN AVERAGE STATISTICAL BASIS; (F) THE SOLUBILITY CHARACTERISTICS OF THE OXYPROPYLATION END PRODUCT IN RESPECT TO WATER AND ORGANIC SOLVENTS BE SUBSTANTIALLY THE RESULT OF THE OXYPROPYLATION STEP; (G) THE RATIO OF PROPYLENE OXIDE PER HYDROXYL IN THE ORIGINAL POLYHYDRIC REACTANT BE WITHIN THE RANGE OF 7 TO 80; (H) THE INITIAL POLYGLYCEROL REACTANT REPRESENT NOT MORE THAN 12 1/2% BY WEIGHT OF THE OXYPROPYLATION END PRODUCT ON A STATISTICAL BASIC; AND (I) THE PRECEDING PROVISOS BEING BASED ON COMPLETE REACTION INVOLVING THE PROPYLENE OXIDE AND THE INITIAL POLYHYDRIC REACTANT; AND (C) WITH THE FINAL PROVISO THAT THE REACTION RATIO OF (A) TO (B) TO ONE MOLE OF (A) FOR EACH HYDROXYL RADICAL PRESENT IN (B). 